Why does the flame always go up? Why the flames keep jumping up

It has to do with the nature of fire.

After the substance is heated, it reaches the ignition point of combustion. Solid combustion without an open flame, such as mosquito coils. Gas combustion produces flames, while liquids and some solids are mostly vaporized after being heated and burned in a gaseous state, so most of the combustion we see has flames.

The air around the flame is heated and less dense than the cold air, so it rises, driving the burning gas upwards. Cold air is replenished from the bottom of the flame, and then heated up again.

Therefore, the upward movement of the flame is caused by the heat rising softer than the cold air.

When the fire is burning, it emits a lot of heat. This heat heats up the surrounding air, and thus, heats up. Since this action is constantly produced during the combustion of the object, the fire always burns upwards.

In everyday life, we observe burning flames, such as lit candles, blazing bonfires, etc., which burn upwards. The ancients did not understand the scientific reasoning and often associated this phenomenon with ghosts and superstitions.

In fact, the upward burning of the flame is the result of the movement of air. When the flame burns, the surrounding air is heated, and since the density of hot air is less than that of cold air, the hot air rises and the cold air from other parts flows over to replenish. As the air rises and flows, the flame is also carried upwards.

When a bonfire is lit, a large amount of hot air rises, and the surrounding cold air quickly flows to replenish it, creating the scene of the bonfire roaring upwards.

But sometimes, the burning flame will flicker and flicker, which is also the "trick" played by the air. Under normal circumstances, when the surrounding air is "calm", the flame is very stable, the temperature is relatively high, and the flame rises relatively high. But in reality, the air flow is affected by various factors, and there will always be some disordered flows, which interfere with the normal order of the hot air rising, so that the flame shows the phenomenon of swaying and shaking.

It turns out that the heat generated during combustion bakes the air around the flames, causing it to expand and become thinner (less dense) and more buoyant. The hot air envelops the flames and rises slowly, causing them to leap upwards. When the hot air rises, it leaves a vacancy, and the hot air continues to flow in from all directions to replenish it.

The replenished air is heated again, expands, thins out, and rises slowly as the buoyancy increases. That's it: Ascend – Replenish – Ascend ......So the flames are always jumping upwards.

The combustion of substances must reach a certain temperature, and oxygen must be aided. Substances do not burn until they reach the ignition point, and they cannot burn without the help of oxygen. Water does not burn, it turns into water vapor when heated.

Splashing a large amount of water on the combustible object will immediately envelop the combustible, absorb the heat of the combustible, reduce the temperature of the combustible, and cut off the air that supports the combustion. However, if the oil catches fire, then you must not splash it with water. Because oil is lighter than water, it cannot be fused with water, and it cannot play a role in extinguishing fires.

Matches are made from sulfur, a substance that burns easily. On the head of the match there are substances that release oxygen when exposed to heat, and they can help the match burn. The matchbox friction surface is made of red phosphorus, which is very flammable.

The matchstick is also made of easy-to-burn willow or pine wood, so that when the match is lightly scratched on the friction surface of the matchbox, the red phosphorus on the friction surface sticks to the match head and burns. Subsequently, the entire match head and matchstick were also lit.

A German alchemist named Brande extracted phosphorus from 50 barrels of urine. He boiled the urine dry and heated it with sand. Brand's choice of the word "phosphorus" is due to the fact that the element glows in the dark, and in Greek, "phosphorus" means "luminous one".

When the fire is burning, it emits a lot of heat. This heat heats up the surrounding air, and the heated air expands heat, becomes lighter, and begins to rise. In the water, light objects always float on the surface of the water.

It's the same in the air. In other words, because the air is heated into an updraft, the direction of the flame is upward.

You can also think of it this way: the fire burns upwards because the rising air or burning hot gas pulls the flame up.

The flame is upward because the air around the flame is heated by the heat released during burning, and the hot air is less dense and will go upwards and carry the flame up.

Very simply, because when burning, the air will be heated, the hot air is rising, and the hot air balloon is using this heat to fly away, so because the fire continues to heat the air, the air around the flame will form an upward trend, the air around the fire will continue to rise, and the colder air on the side will continue to replenish, forming an upward air flow, which in turn will drive the flame upward.

Flames are produced by the combustion of volatile flammable substances, most of which are burned first into gaseous state and then burned, and the vapor density is lower than that of air when burning, so it will go upward.

The flame is up because the combustible gas floats upward, and you can let it burn downward

The density of the air will become smaller, it will go up, and the air around it will come from below to replenish, and the flame will go up.

After heating, the local oxygen in the air decreases, the pressure decreases, and the surrounding air will be replenished, and it will rise up, and the flame will go upward.